delta_2D_Ising
plain-language theorem explainer
The definition supplies the exact value 15 for the magnetic critical exponent in the two-dimensional Ising universality class. Workers on critical phenomena in the Recognition Science setting cite it to close the Widom scaling identity. The assignment is a direct constant with no further reduction.
Claim. The critical exponent satisfying $M(h) = h^{1/δ}$ at the critical temperature for the two-dimensional Ising model equals 15.
background
The module derives critical exponents from φ-scaling near phase transitions. Thermodynamic quantities diverge as $C ∼ |t|^{-α}$, $M ∼ (-t)^β$, $χ ∼ |t|^{-γ}$, and $ξ ∼ |t|^{-ν}$, with $t$ the reduced temperature. Recognition Science obtains universality from J-cost fluctuations structured by the self-similar fixed point φ, as stated in the module target.
proof idea
The definition is a direct constant assignment of the known exact value 15 for the 2D Ising δ. No lemmas or tactics are invoked; the declaration simply binds the real number for downstream use in scaling identities.
why it matters
It supplies the missing constant for the Widom relation theorem that verifies γ = β(δ − 1) in the 2D case. This supports the module goal of universal exponents from φ-scaling and links to the Recognition Composition Law through the underlying J-cost. The value closes one link from T5 J-uniqueness to thermodynamic scaling relations.
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